This application describes the commercialization of the Geodesic Transcranial Electrical Neuromodulation (GTEN) technology to achieve noninvasive neuromodulation with improved spatiotemporal precision. The GTEN system enables both EEG source analysis and configurable electrical neuromodulation with the 256 electrodes of the Geodesic Sensor Net. Now in beta release to selected research customers, the GTEN technology will be fully commercialized as a medical device through addressing four specific aims guided by the goals for noninvasive neuromodulation in the BRAIN Initiative. (1) We will improve focal current delivery at deep as well as superficial brain locations with a novel targeting algorithm (Discriminative Cortical Source Vectoring) implemented with a high resolution conductivity model of the human head. (2) Both simulation and experiment will be used to minimize extraneous stimulation to non target regions while quantifying current delivered to all brain regions. (3) We will design and test a placebo mode to allow definitive clinical trials. (4) Closed loop operation will be achieved by guiding the localization and phase of GTEN intervention with simultaneous monitoring of source-localized EEG. In the validation of closed-loop operation, the EEG rhythms will be those of slow wave sleep, and they will be hypothesized to be enhanced in both depth and length during the night's sleep. Completing the aims of this SBIR will create a dEEG-guided noninvasive dense array electrical neuromodulation technology as a powerful, precise, and inexpensive technology for both research and clinical practice.